--- /dev/null
+--- a/globals.c
++++ b/globals.c
+@@ -31,6 +31,8 @@
+ const struct in_addr inaddr_any = { INADDR_ANY };
+ #endif
+
++int g_family = AF_INET;
++
+ in_port_t g_udp_port = 161;
+ in_port_t g_tcp_port = 161;
+ int g_timeout = 100;
+--- a/mini_snmpd.c
++++ b/mini_snmpd.c
+@@ -54,6 +54,10 @@ static void print_help(void)
+ fprintf(stderr, "-d, --disks nnn set the disks to monitor (/)\n");
+ fprintf(stderr, "-i, --interfaces nnn set the network interfaces to monitor (lo)\n");
+ fprintf(stderr, "-I, --listen nnn set the network interface to listen (all)\n");
++#ifdef __IPV6__
++ fprintf(stderr, "-4, --ipv4 use IPv4 (default)\n");
++ fprintf(stderr, "-6, --ipv6 use IPv6\n");
++#endif
+ fprintf(stderr, "-t, --timeout nnn set the timeout for MIB updates (1 second)\n");
+ fprintf(stderr, "-a, --auth require authentication (thus SNMP version 2c)\n");
+ fprintf(stderr, "-v, --verbose verbose syslog messages \n");
+@@ -117,7 +121,7 @@ static void handle_udp_client(void)
+ #endif
+
+ /* Call the protocol handler which will prepare the response packet */
+- inet_ntop(my_af_inet, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
++ inet_ntop(g_family, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
+ if (snmp(&g_udp_client) == -1) {
+ lprintf(LOG_WARNING, "could not handle packet from UDP client %s:%d: %m\n",
+ straddr, sockaddr.my_sin_port);
+@@ -132,7 +136,7 @@ static void handle_udp_client(void)
+ /* Send the whole UDP packet to the socket at once */
+ rv = sendto(g_udp_sockfd, g_udp_client.packet, g_udp_client.size,
+ MSG_DONTWAIT, (struct sockaddr *)&sockaddr, socklen);
+- inet_ntop(my_af_inet, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
++ inet_ntop(g_family, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
+ if (rv == -1) {
+ lprintf(LOG_WARNING, "could not send packet to UDP client %s:%d: %m\n",
+ straddr, sockaddr.my_sin_port);
+@@ -176,7 +180,7 @@ static void handle_tcp_connect(void)
+ }
+ tmp_sockaddr.my_sin_addr = client->addr;
+ tmp_sockaddr.my_sin_port = client->port;
+- inet_ntop(my_af_inet, &tmp_sockaddr.my_sin_addr, straddr, sizeof(straddr));
++ inet_ntop(g_family, &tmp_sockaddr.my_sin_addr, straddr, sizeof(straddr));
+ lprintf(LOG_WARNING, "maximum number of %d clients reached, kicking out %s:%d\n",
+ MAX_NR_CLIENTS, straddr, tmp_sockaddr.my_sin_port);
+ close(client->sockfd);
+@@ -190,7 +194,7 @@ static void handle_tcp_connect(void)
+ }
+
+ /* Now fill out the client control structure values */
+- inet_ntop(my_af_inet, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
++ inet_ntop(g_family, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
+ lprintf(LOG_DEBUG, "connected TCP client %s:%d\n",
+ straddr, sockaddr.my_sin_port);
+ client->timestamp = time(NULL);
+@@ -211,7 +215,7 @@ static void handle_tcp_client_write(clie
+ sockaddr.my_sin_addr = client->addr;
+ sockaddr.my_sin_port = client->port;
+ rv = send(client->sockfd, client->packet, client->size, 0);
+- inet_ntop(my_af_inet, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
++ inet_ntop(g_family, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
+ if (rv == -1) {
+ lprintf(LOG_WARNING, "could not send packet to TCP client %s:%d: %m\n",
+ straddr, sockaddr.my_sin_port);
+@@ -246,7 +250,7 @@ static void handle_tcp_client_read(clien
+ sockaddr.my_sin_port = client->port;
+ rv = read(client->sockfd, client->packet + client->size,
+ sizeof (client->packet) - client->size);
+- inet_ntop(my_af_inet, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
++ inet_ntop(g_family, &sockaddr.my_sin_addr, straddr, sizeof(straddr));
+ if (rv == -1) {
+ lprintf(LOG_WARNING, "could not read packet from TCP client %s:%d: %m\n",
+ straddr, sockaddr.my_sin_port);
+@@ -304,7 +308,11 @@ static void handle_tcp_client_read(clien
+
+ int main(int argc, char *argv[])
+ {
++#ifdef __IPV6__
++ static const char short_options[] = "p:P:c:D:V:L:C:d:i:I:t:T:avl46h";
++#else
+ static const char short_options[] = "p:P:c:D:V:L:C:d:i:I:t:T:avlh";
++#endif
+ static const struct option long_options[] = {
+ { "udp-port", 1, 0, 'p' },
+ { "tcp-port", 1, 0, 'P' },
+@@ -316,6 +324,10 @@ int main(int argc, char *argv[])
+ { "disks", 1, 0, 'd' },
+ { "interfaces", 1, 0, 'i' },
+ { "listen", 1, 0, 'I' },
++#ifdef __IPV6__
++ { "ipv4", 0, 0, '4' },
++ { "ipv6", 0, 0, '6' },
++#endif
+ { "timeout", 1, 0, 't' },
+ { "traps", 1, 0, 'T' },
+ { "auth", 0, 0, 'a' },
+@@ -396,6 +408,14 @@ int main(int argc, char *argv[])
+ case 'v':
+ g_verbose = 1;
+ break;
++#ifdef __IPV6__
++ case '4':
++ g_family = AF_INET;
++ break;
++ case '6':
++ g_family = AF_INET6;
++ break;
++#endif
+ case 'l':
+ print_version();
+ exit(EXIT_ARGS);
+@@ -435,12 +455,12 @@ int main(int argc, char *argv[])
+ #endif
+
+ /* Open the server's UDP port and prepare it for listening */
+- g_udp_sockfd = socket(my_pf_inet, SOCK_DGRAM, 0);
++ g_udp_sockfd = socket((g_family == AF_INET) ? PF_INET : PF_INET6, SOCK_DGRAM, 0);
+ if (g_udp_sockfd == -1) {
+ lprintf(LOG_ERR, "could not create UDP socket: %m\n");
+ exit(EXIT_SYSCALL);
+ }
+- sockaddr.my_sin_family = my_af_inet;
++ sockaddr.my_sin_family = g_family;
+ sockaddr.my_sin_port = htons(g_udp_port);
+ sockaddr.my_sin_addr = my_inaddr_any;
+ socklen = sizeof (sockaddr);
+@@ -457,7 +477,7 @@ int main(int argc, char *argv[])
+ }
+
+ /* Open the server's TCP port and prepare it for listening */
+- g_tcp_sockfd = socket(my_pf_inet, SOCK_STREAM, 0);
++ g_tcp_sockfd = socket((g_family == AF_INET) ? PF_INET : PF_INET6, SOCK_STREAM, 0);
+ if (g_tcp_sockfd == -1) {
+ lprintf(LOG_ERR, "could not create TCP socket: %m\n");
+ exit(EXIT_SYSCALL);
+@@ -474,7 +494,7 @@ int main(int argc, char *argv[])
+ lprintf(LOG_WARNING, "could not set SO_REUSEADDR on TCP socket: %m\n");
+ exit(EXIT_SYSCALL);
+ }
+- sockaddr.my_sin_family = my_af_inet;
++ sockaddr.my_sin_family = g_family;
+ sockaddr.my_sin_port = htons(g_tcp_port);
+ sockaddr.my_sin_addr = my_inaddr_any;
+ socklen = sizeof (sockaddr);
+--- a/mini_snmpd.h
++++ b/mini_snmpd.h
+@@ -255,6 +255,7 @@ typedef struct demoinfo_s {
+
+ extern in_port_t g_udp_port;
+ extern in_port_t g_tcp_port;
++extern int g_family;
+ extern int g_timeout;
+ extern int g_auth;
+ extern int g_verbose;